On Wednesday, July 30, 2014 2:28:28 PM UTC-7, Steve Freeman wrote:
I have an SZD55 flying under an experimental/exhibition certificate in the US. It was manufactured at the factory in Poland. I have made some changes to the instrumentation in the panel and a few other items. Can anyone confirm that all that is required by the FAA is a logbook entry by myself stating what was done followed by my signature and pilot certificate number and then a statement by an IA explaining they supervised the work and their signature etc.

An A+P can sign this off and you can do the work but you should have an A+P working with you and following along. I have no problem signing off work others have done if I know them and they get with me ahead of time so I can review what and how they are going to do the work but you will need to have it signed off by an A+P. Read your operating limitations you should find somthing in there about alterations.